Two  Examples  of    Probabilis2c  Transmission  Planning  

At  BPA  

Bill  Mi&elstadt,  Chuck  Ma&hews  and    Paul  Ferron  

Grid  Transforma<on  March  20,  2013  

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Topics  

•  BPA  Transmission  Outage  Data  using  the  Transmission  Outage  Manager  Program  

•  Benefits  Analysis  Program  (1996)  

•  Kangley  –  Echo  Lake  500  kV  reclassifica<on  example  

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Transmission  Outage  Management  Program    (TOM)  

•  Maintains  an  outage  data  base  for  BPA  system  transmission  lines  

•  Allows  sta<s<cs  to  be  grouped  in  many  different  ways  to  es<mate  the  effect  of  a  change  in  design  or  expected  outage  rate  of  a  future  transmission  facility.  

_______________________________  Program  wri&en  by  Sudhir  Agrawal  (General  Reliability)  

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Ways  To  Sort  Data  •  Voltage  Class  (500  kV,  345  kV,  230  kV,…)  •  Region  of  system    •  With  or  without  OHGW  •  Outage  <me  (temporary  or  sustained)  •  Fault  cause  (line  or  terminal)  •  Common  or  separate  tower  

For  example:  What  is  expected  outage  rate  for  a  10-­‐mile  500  kV  double-­‐circuit  line  located  east  of  the  Cascades  on  common  tower  with  OHGW  and  high-­‐speed  reclosing?  

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Benefits  Analysis  Program  

•  Planning  effort  applied  to  14  area  service  transmission  projects  (1996).  

•  Cost/Benefit  Analysis:  project,  societal,  BPA  •  Outage  sta<s<cs:  frequency  and  dura<on  •  Load  dura<on  curve  of  area  or  region  used,  incremented  by  <me  (next  slide)  

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0!

1000!

2000!

3000!

4000!

5000!

6000!

0! 500! 1000! 1500! 2000! 2500! 3000!

Loa

d L

evel

(MW

)

Hours of Year

Yearly Incremented Load Duration Curve

With  Project  

Without  Project  

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Kangley  –  Echo  Lake  500  kV  Case    

•  9.5  mile  common  ROW  of  two  lines  with  one  common  breaker  and  half  terminal  

•  2715  mile-­‐years  of  historical  data  spanning  a  period  of  17  years  for  es<ma<ng  MTBF  

•  Adjusted  historical  data  for  load  dura<on  analysis  

•  Robust  Line  mi<ga<on  factors    

•  Adjusted  from  Category  C  to  D  by  WECC  

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Exposure  Analysis    Three-­‐Year  Record  

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Exposure  Analysis  Load-­‐Dura2on  Curve  

•  Increasing  to  41  hours/year  by  2010  

?  Concluding  Ques<ons  ?  

•  How  can  we  be&er  use  line  and  sta<on  historical  outage  informa<on  in  making  decisions  on  future  projects?  

•  How  can  we  be  be&er  use  historical  and  projected  flow  pa&erns  in  making  decisions  on  future  projects?  

•  What  tools  are  available?  

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Concluding  Sugges2ons…  •  Increase  use  of  sta<s<cal  outage  informa<on  and  forecasted  projec<ons  on  path  use  in  comparing  alterna<ves  and  selec<ng  network  robustness  features.  

•  Examine  prac<cal  ways  to  minimize  the  impact  of  extreme  events.  

•  Con<nue  to  improve  situa<onal  awareness.  •  Minimize  system  readjustment  <me  to  reduce  risk  posed  by  a  next  con<ngency.  

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Ques2ons?  

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Reducing Risks

References  

1.  Outage  Probability  of  Lines  Sharing  a  Common  Corridor,  W.A.  Mi&elstadt,  D.  Paul  Ferron,  S.  K.  Agarwal,  Ron  E.  Baugh    8th  Interna<onal  Conference  Probabilis<c  Methods  Applied  to  Power  Systems,  September  12-­‐16,  2004.    

2.  Robust  Line  Design  Features,  WECC  Reliability  Probability  Evalua<on  Work  Group  approved,  December  2003.    

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A.   Monroe  –  Custer  500,  1&2    89  miles  

B.   Paul  –  Allston  500,  1&2    48  miles  C.   Custer  –  Ingledow  500,  1&2  23  miles  

D.   2700  Mile-­‐years  of  historical  data  E.   West  of  Cascades  sample  F.   None  shield  wire  equipped  

G.   Paul-­‐Allston  SPR  Equipped  

Sta2s2cal  Base  Used